Furnace



A. L. STEVENS.

" FuRNAcl-z.

APPLICATION FILED JUNE 26,1916.

1,315,252. Pamdsept. 9,1919.

5 SHEETS-SHEET 1.

A. L. STEVENS.

FuRNAE. APPUCATION FILED IUNE 26.1916.

Patented sept. 9, 1919'.

5 SHEETS- SHEET 2 YA Arron/5v5 A. L. STEVENS.

` y FURNAGE. APPLICATION FILED IuNE 25.1916.

1 ,3 1 5 ,25 2 Patented Sept. 9, 1919.

5 SHEETS-SHEET 3.

INVENTO/ A TTORNEY J A. L. STEVENS.

FURNACE.

APPLlcAloN FILED JUNE 26.1916.

PatentedSept. 9,1919.

5 SHEETS-SHEET 4.

' /NVENT/i m4 BY fama/L A. L. STEVENS. FURNACE.

APPLICATION FILED JUNE 26.1916.

Patented Sept. 9, 1919.

5 SHEETS-SHEET 5.

A TTOR/VEY ABTHURL. STEVENS, 0F CHICAGO, ILLINOIS.

FURNACE.

Specicatio'n of Letters Patent.

Patented Sept. 9, 1919.`

Application filed .Tullel 26. 191.6. Serial No. 105,895;

To` all whom it may concern Be it known that I, ARTHUR L. STEVENS,

a citizen of the United States, residin at Chicago, in the county ofCook and tate i Vf Illinois, have invented certain new and usefulImprovements in Furnaces, of which the following is a specification.

My invention relatesy to the construction of a furnace having arelatively long,l narrow combustion chamber and hearth, such,

for example, as a drag furnace employed fory heatingy metal rods, bars,or the like.

The principal object of the invention is to provide a furnace of thischaracter operating on the regenerative principle so designed andconstructed as to insure uniform and` high temperature in the combustionchamber for the full length thereof with economy of fuel.

A further object is to provide a furnace of this type which will berelatively small .and compact in its structure, which will beinexpensive to build, and in .which the cost of maintenance andrepairswill be reduced to a minimum. The furnaceof my invention isintended particularly for fluid fuel and is` especially adapted forburning a lean producer gas.

A furnace constructed in accordance with the invention and having thesedesirable features is shown in the accompanying drawings. The invention,however, is not to be understood as narrowly limited to this preferredembodiment as the structural details of the furnace are susceptible ofmodification to a considerable extent without departure from theprinciples of the invention lwhich I desire to cover as broadly as thestate of the art will warrant without re ard .to matters of specificconstructlon which wlll necessarily vary in the particular installationaccording to the service required of the furnace. In the drawings Figure1 is a lan view of the furnace.

Fig. 2 is a si e elevation thereof.

Fig. 3 is a sectional plan on an enlarged scale.

Fig. 4 is a sectional view online 4--4 of Fig. 5, illustrating theconstruction of one of the reversing valves for the fuel and lair supplypipes.

Fig. 5 is a sectional View on llne 5 -5 of Fig. 4.

Fig. 6 is a longitudinal, vertical sectional view through the furnace.

, vention solves the difficulty by Fig, 7 is a cross sectional view online of F 6. Flg. 8` is a cross sectional view on line A8--8f of Fig. 6,and

Fig. 9` is a fragmentary, diagrammatic View of the furnace, inperspective, with parts in section, to illustrate lparticularly the flowof the gases through the combustion chamber, ducts and regenerators.

Like characters of reference desi ate like parts in the several liguresof the rawings.

The furnace structure, which consists preferably of brickwork 10 coveredby side sheathing plates 1'1 and top plates 12 of metal, is supported onmetal bottom plates 13, 14, carried by angle irons 15 and I-beams 16which are, in turn, supported on the transverse beams 17 secured to legs18.V These are matters of constructional detail and may be varied asoccasion demands.

The furnace shown for the purpose of illustrating the principles of myinvention is a drag furnace having a long, relatively narrow combustionchamber 19. The furnace is intended for heating metal rods,

bars, or the like, which are drawnl throughV the furnace `from end toend across hearth 2t). The bars are introduced into the furnace throughopening 21 at one end which is preferably provided with a door 22 andare withdrawn from the furnace through `opening 23 at the other end ofthe hearth. The length of the hearth and its narrowness, in a furnace ofthis type, makes it diiiicult to obtain uniform heating of thecombustion chamber with economy of fuel. If the flames are made to passlengthwise through the furnace from one end to the other, thetemperature at the end adjacent the source of heat is higher than thetemperature at.

the other end. The hearth is too narrow to make it feasible to pass theflames directly across the hearth from side to side; and suchconstruction would be uneconomical as it would be impossible to mobtaina hightemperature and complete combustion. My in`' dividing the'combustion chamber into lengths, as it were', and heating the lengthsseparately. Moreover, I provide an arrangement of the regeneratorfs, `elburners, air.l and discharge ducts and discharge ports for theregenerators whereby it is ossible to obtain a com- 4'plete combustion oa cold gas and the maintenance of a high temperature inthe comthefurnace.

bustion chamber with a relatively low telnperature in the outflowinggases, all of which results in economy of fuel and maintenance cost.

VThe furnace is provided with a plurality of regenerators A, B, C, Dwhich are arranged above the combustion chamber, each regenerator beingsubstantially the Width of The regenerators are separated by walls 24,25, 26, supported Von arches 27.

Associated With'each of the regenerators A, B, C and D are sets ofangular ducts 28, 28", 28", 28". The ducts 28a, 28 open into thecombustion chamber from one side thereof and the ducts 28", 28l openinto the chamber from the other side of the furnace. 29 is a fuel supplypipe and 30 is a branch pipe, one end of which leads to a pipe 31extending along one side of the furnace. The other end leads across thefurnace to a pipe 32 extending along the other side thereof. The pipes31, 32 are provided with a plurality of burners 33, one for each of theducts 28a, 28", 28, 28d. Air under pressure is supplied to the furnacethrough the regenerators from air supply pipe 34 which may be connectedwith any suitable fan or compressor (not shown). The supply pipe 34 isconnected by means of pipe' 35 to branch pipes 36, 37, extending overthe furnace on opposite sides thereof. One extremity 38 of pipe 36extends into a channel 36a in the side Wall opening into a duct 39 inthe end wall 40 of the furnace adjacent regenerator A, which ductcommunicates by port 41 with said regenerator. The extremity 42 of thepipe 36 extends into a channel 42 in the side wall opening into a duct43 in the partition Wall 25 between regenerators B and C, this ductcommunieating by means of port 44 with regenerator C. One extremity 45of pipe 37 extends into a channel 45" Which opens into the duct 46 inthe partition wall 24 between regenerators A and B. This ductcommunicates by port 47 with regenerator B. The other extremity 48 ofpipe 37 extends into a channel` 48a opening into duct 49 formed inpartition wall 26 between regenerators C and D, this ductcommunicatingby port 50 with regenerator D. The regenerators A, B, C and D exhaustdirectly to the atmosphere through exhaust ports 51a, 51", 51c and 51d,respectively, the exhaust ports opening from the ducts 39, 46,43, 49,just described. i

I The exhaust ports are controlled by slide valves 52 preferablyattached to one of a pair of links 53, 53 which are pivoted to cranks 55rigidly secured to shafts 56 at opposite ends of the furnace, one ofthese llliaft; being revoluble by means of a han- Interposed between thefuel supply pipe 29 and the extremities of pipe 30 leading to pipes 31and 32, respectively, is a valve E adapted to direct the fuel to theburners on either side of the furnace, at the same time shutting it offfrom the burners on the other side. A similar valve F is interposedbetween the air supply pipe 34 and the extremities of pipe 35 leading toair pipes 36, 37 on opposite sides o f the furnace.

The valves E and F may be identical and the preferred constructionthereof is shown in Figs. 4 and 5. 58 is a casing formed with a neck 59for attachment to the supply pipe 29 or 34 as the case may be. Thecasing is formed with openings at each end in which are fitted spiders'60'forming valve seats and providing bearings 61 for the stems 62 of adouble valve member 63 adaptJ ed to be reciprocated by finger 64 whichenters a slot 65 in the-valve member and is secured to ashaft 66 whichemerges from the valve casing through a gland 67. 1The shaft 66 iscommon to both valves E and F. It is rocked by means of an arm 68rigidly secured thereto, connected by a link (39 with the lever 57,which, as above described, serves to shift the slide valves controllingthe exhaust ports from the regenerators.

Operation: The furnace is firedrst from one side and then from theother, the air introduced with the fuel being heated, in each case, bypassing through regenerators throu h which the products of combustionhave een discharged prior to the reversal of the valves. The drawingsshow the fuel and gas as entering the portions of the combustion chamberunder regenerators B and D and the products of combustion as beingdischarged from the combustion chamber on the opposite side thereofthrough the ducts communicating with portions of the combustion chamberunder regenerators A and C. Gas valve E is in position to admit gas tothe pipe 31 shutting the gas olf from gas pipe 32 on the opposite sideof the furnace. Air valve F is in 4position to admit air to pipe 37 andto close air pipe 36. The air, which is supplied under pressuresufiicient to maintain the proper temperature in the combustion chamber,passes from pipe 37 into d'uct 46 (see Fig. 9) through port .47 intoregenerator B, thence through the angular ducts 28" into the combustionchamber. A gas burner 33 leads into each of the ducts 28" and the gas isthoroughly mixed with the heated air when it enters the combustionchamber. The provision of a plurality of ducts for the regenerator and aplurality of gas burners prevents the stratification of the fuel andinsures proper mixture thereof with the air. The flame in the combustionspace below regenerator B divides and passes in opposite. directionslengthwise of the furnace. as indicated by the arrows in Fig. 3. lartpasses ramena into the con'rbustion space under regenerator A. and isdischarged through ducts 28a into the regenerator A, from which theproducts of combustion are discharged directly to the atmosphere throughthe discharge ports 51a which are open (Fig. l). rlhe dames and productsof combustion traveling in: the other direction pass into the combustionspace below regenerator C and are discharged through ducts 28,regenerator C and exhaust ports 51e. Air and gas at the saine time areintroduced into the combusltion space under regenerator D through ducts28d. 'llhe products of combustion pass lengthwise of the combustionspace .under regenerator ll) into the combustion space under regeneratorC and are discharged through ducts 28 and regenerator C. lin this mannerthe entire combustion chamber is uniformly heated in sections. At thesame time the dames are allowed to travel far enough -lengthwise of therelatively narrow combustion chamber so that the combustion is complete.By a proper proportioning. ofthe outlet ports 51a, 5l.c and properregulation of the air pressure in the air supply pipes, depending uponthe service for which the furnace is intended, it is possible todischarge the gases of combustion directly to the atmosphere, withoutthe employment of stack draft and at a relatively low temperature, andto maintain -a neutral. or even a slightly reducing flame of very hightemperature in the combustion chamber by producing in the combustion.chamber a pressure justa trifle above atmospheric pressure sufficient toprevent the inflow of air through the working openings at opposite endsof the furnace, which, during the operation of the furnace, mustnecessarily be open at least to a considerable extent. 'llhe fuelpreferably is not heated. lit is possible to use a lean, cold producergas which is relatively cheap and which may be cleaned before it isintroduced into the furnace. This circumstance, and the fact that thegases are discharged at a relatively low temperature, besides ermittingeconomy of fuel, makes it possible to simplify the construction of thefurnace and to minimize cost of maintenance. The piping of the furnacemay be made relatively small. The valves need not be water cooled. Thesize of the regenerators may be reduced to a minimum. The regeneratorsand other parts of the furnace do not require cleaning.

furnace having these general characteristicsl is described and claimedin my copending application Serial No.l 953-199V filed May 19', 1916.and is not genericallyclaimed herein. The invention of the'presentapplication relates more particularlv to the application of theseprinciples of furnace construction to a drag furnace or other furlillnace in which there is a long and relatively narrow combustion chamberrequiring the maintenance of a uniform and high temperature. A

By reversing the valves the furnace may be fired from the other'side, inwhich case the fuel and air enters the combustion chamber at pointsunder regenerators A and C and the lproducts of combustion aredischarged through regenerators B and. D.

The arrangement of the regenerators tandem above the combustion chambergives the furnace structure very desirable compactness and accessibilityin the event that repairs have to be made.,

l claim': v

1. A furnace having a relatively long, narrow combustion chamber,provided on one side with inlet ports for the introduction of air andfuel at a plurality o-f points remote from each other, and provided onthe other side with outlet ports at a corresponding number of pointsremote from each other and in staggered relation with the said inletports, whereby the chamber is heated in lengths byy a plurality ofseparately induced currents of gas in combustion.

2. A furnace comprising a relatively long, narrow combustion chamber,provided on one side with inlet ports for the introduction of air andfuel at a plurality of points remote from each other, and provided onthe other side with outlet ports at a corresponding number of pointsremote from each other and in staggered relation with the said inletports, whereby the chamber is heated in lengths bya plurality ofseparately induced currents of gas in combustion, and a plurality ofregenerators a-rranged longitudinally of the furnace above thecombustion chamber which alternately receive air and discharge theproducts of combustion.

3. rllhe combination with a furnace structure havingl a relatively long7narrow combustion chamber, of means for introducing fuel and air intothe combustion chamber from one sideftl-iereof, means for dischargingthe 4productsof the combustion of the fuel thusfint'roduced at a `placediagonally remote from the place of introduction of the fuel and air,and regenerators arranged' longitudinally of the combustion cli-am ierthrough which the incoming air and outgoing products of combustion pass.

4. The combination with a furnace structure of the reversibleregenerative type having al relatively long. narrow combustion chamber,of means for introducing fuel and air into said combustion chamber at aplurality of places disposed lengthwise of said chamber, means fordischarging the products of the combustion of said fuel at a pluralityof places diagonally remote from the places of introduction of the fueland air, and regenerators arranged longltudifill atA

lllll nally of the combustion chamber through which the incoming air andoutgoing products of combustion pass.

5. The combination with a furnace structure having a relatively long,narrow combustion chamber, of means for introducing fuel and air intosaid combustion chamber at a p-lurality of placesv disposed lengthwiseof said chamber, means for discharging the products of combustion at aplurality of places on the other side of the furnace longitudinallyremote from the places of introduction of the fuel and air, andregenerators arranged in alternate sets extending longitudinally of thecombustion chamber through which the incoming air and outgoing productsof combustion pass.

6. The combination with a furnace structure having a relatively long,narrow combustion chamber, of means for introducing fuel andv air intothe combustion chamber from one side thereof, means for discharging theproducts of combustion from the other side thereof at a place diagonallyre- -mote from the place of introduction of the fuel and air, and aplurality of regenerators arranged longitudinally of the furnace abovethe combustion chamber which alternately receive air and discharge theproducts of combustion.

7. The combination with a furnace structure having a relatively long,narrow combustion chamber, of means for introducing fuel and air intothe combustion chamber from one side thereof, means for discharging theproducts of combustion from the other side thereof at a placelongitudinally remote from the place of introduction of the fuel andair, and pairs of regenerators comprising a plurality of regeneratorsections arranged in tandem longitudinally of the furnace above thecombustion chamber through which the incoming air and out going productsof combustion pass in alternation, each regenerator being substantiallyas wide as the combustion chamber.

' 8. The combination with a furnace structure having a relatively long,narrow combustion chamber, of means for introducing fuel and air intosaid combustion chamber at a plurality of places disposed lengthwise oflsaid chamber, means for discharging the products of combustion at aplurality of places on the other side of the furnace longitudinallyremote from the places of introduction of the fuel and*4 air, and aplurality of regenerators arranged longitudinally of the furnace abovethe combustion chamber which alternately receive air and discharge theproducts of combustion.

9. The combination with a furnace structure having a relatively long,narrow combustion chamber, of means for introducing fuel and air intosaid combustion chamber at a plurality of places disposed lengthwise oftion chamber.

10. A furnace comprising a relatively long, narrow combustion chamber,ducts on opposite sides thereof in staggered relation for theintroduction of air and discharge of products ofl combustion,- fuelburners arranged in said ducts and reversing valves whereby the air andfuel may be introduced into the combustion chamber on either side andthe products of combustion discharged on the opposite side.

11. A furnace comprising a relatively long, narrow combustion chamber,ducts on opposite vsides thereof in staggered relation for the.introduction of air and discharge of products of combustion, fuelburners arranged in said ducts, two sets of regenerators communicatingwith the ducts on opposite sides of the furnace respectively, andreversing valves whereby the air may be introduced into the combustionchamber through either set of regenerators and the products ofcombustion discharged therefrom through the other set of regenerators.

12. A 'furnace comprising a relatively long, narrow combustion chamber,ducts on opposite sides thereof in staggered relation for theintroduction of air and discharge of products of combustion, fuelburners arranged in said ducts, two sets of regenerators communicatingwith the ducts and arranged in alternation lengthwise and above thecombustion chamber, and reversing valves whereby the air may beintroduced into the combustion chamber through either set ofregenerators and the products of combustion discharged therefrom throughthe other set of regenerators.

13. A furnace comprising a relatively long, narrow combustion chamber,ducts on opposite sides thereof in staggered relation for theintroduction of air and discharge of products of combustion, fuelburners arranged in said ducts, two'sets of regenerators communicatingwith the ducts on opposite sides of the furnace, respectively, providedwith discharge ports opening directly to the atmosphere and arrangedabove the combustion chamber, air pipes for introducing air underpressure into the regenerators, and reversing valves whereby the air maybe introduced into the furnace through either' set of regenerators andthe products release of combustion discharged therefrom through theother set of regenerators.

lll. A furnace comprising a relatively long, narrow combustion chamber,ducts on opposite sides thereof in staggered relation o for theintroduction of air and discharge of products of combustion, fuelburners ar- .lli

generators, and reversing valves 'whereby' the air may be introducedinto the furnace through either set yof regenerators and the products ofcombustion discharged theretitl from through the other set vofregenerators.

15. A furnace comprising a relatively long, narrow combustion chamber,ducts on opposite sides thereof in stag ered relation for theintroduction of air an discharge of4 productsoof combustion, a gassupplyv pipe and fuel burners the latter being arranged in said ducts,two sets of rcg'enerators coinmunicating with the ducts on oppositesides of theI furnace respectively, provided with discharge portsopening directly to the atmosphere and arran ed above the combustionchamber, air pipes or introducing airA under pressure into theregenerators, and reversing valvesfor said gas pipe,

air pipes and regenerator discharge ports whereby the air maybeintroduced .into the furnace through either set of regenerators and gasthrough the corresponding set lof burners and whereby the products ofcombustion may be .discharged therefrom through the other set ofregenerators.

16. A` furnace comprising a relatively long, narrow combustion chamber,ducts on l opposite sides thereof in staggered relation for theintroduction of. air and discharge of products of combustion, a gas`supply pipe and fuel burners the latter being arranged in said ducts,two sets of regenerators cominunicating with the ducts on opposite sidesof the furnace respectively, provided with discharge ports openingdirectly to the at inosphere and arranged above the combustion chamber,air pipes for introducing air under pressure into the regenerators,reversing valves for said gas pipe, air pipes and regenerator discharge,ports whereby the air may be introduced into the furnace through eitherset of regenerators and gas through the corresponding set lof burnersand wherepipes for in- Std by the products of combustion may be.discharged'therefrom through the other set of regenerators,. and 'meansfor simultaneously operating said valves.

17. ln a furnace, the' combination of a combustion chamber, two sets ofregenerators of substantially the same width as the combustion chamberarranged lengthwise thereof and above the same and provided with.discharge openings in the top, ducts leading from one set ofregenerators into the combustion chamber on, one side and similar ductsleading-from the other set of regenerators into the combustion chamberon the other side, a gassupply pipe, branch pipes connected therewithand' extending valong opposite sides of the furnace and provided withburnersprojecting into said ducts,"a valve for directing the gas to theburners on either side-of the furnace, shut- Ating it od from theburners on the opposite side, .an air supply pipe for air underpressure" provided with branches extending along opposite sides of thefurnace,one comv municating with one set of regenerators, the other withthe other set, an air valve to direct the air into either set ofregenerators and shut it od from the other set, and valves po close thedischarge ports of the regenerors.

18. lin a furnace, the combination of a combustion chamber, two sets ofregenerators of substantially the saine width as the combustion Achamberarranged lengthwise .thereof and above the same and provided withdischarge openings in the top, ducts leading from one set ofregenera'tors into the combustion chamber on one side and similar ductsleading from the other set of regenerators intothe combustion chamber onthe i other side, a gas supply pipe, branch pipes connected therewithand extending along opposite sides of the furnace and provided withburners projecting into said ducts, a valve for directing the gas to theburners on either side of the furnace, shutting it od from theburnersvon the opposite side, an air supply pipe for air under pressureprovided with branches extending along oppositesides of the furnace, onecommunicat in with one set of regenerators, the other with the otherset, an air valve to direct the air into either set of regenerators andshut 1t' olf from the other set, valves to close the discharge ports ofthe regenerators, and

ARTHUR L. sravENs.

as to reverse them with ica

